1. Technical Field
The present invention relates to an information recording medium for recording digitized information, and more particularly to an information recording medium having an area for managing defects of the medium. The present invention relates to a method and an apparatus for recording information in such information recording medium.
2. Related Art
In the background of advancement of information technology society, transmission of information continues to be faster in speed and greater capacity, and the information recording medium for recording and storing the information is also demanded to be faster in speed and greater in capacity.
In a rewritable recording medium represented by an optical disk, in order to assure reliability of recorded information by overcoming initial defects such as pin holes generated in the manufacturing process or secondary defects such as flaw and stain occurring due to use, generally, a function known as replacement process is implemented. In the replacement process, if a track that is supposed to record certain information has an error and is regarded as defective, this track is not used, and information is recorded on another replacement track.
In a data recording track, individual address information is pre-recorded in a different system (with change in groove shape, for example) from the recording data (with phase change of recording film, for example). In relation to the prerecorded address information, generally, a relative position of the recording position of address information and the recording data are determined in advance. In an apparatus for writing information in such an information recording medium, the data is recorded and reproduced while referring to the individual address information, and therefore in the case of a replacement process, the address information of the defective track and the address information of the track replacing the defective track must be managed as a history of the replacement process. Such process is generally called “defect management.”
In the case of a rewritable recording medium, in particular, since one medium may be used by plural apparatuses, it often includes a defect management area to be used exclusively for defect management.
Incidentally, if an attempt is made to raise the recording density of information in order to increase the capacity of the information recording medium, a higher precision is demanded in recording and reproduction of information. On the other hand, recording and reproducing characteristics vary depending on manufacturing fluctuations of a recording medium and an apparatus, or temperature changes and other factors in the operating environment of the apparatus. Therefore, to record and reproduce with precision regardless of any environmental changes, optimization of the recording and reproducing conditions is required.
To solve this problem, various ideas have been proposed, including a method of optimizing the recording and reproducing conditions by combining the recording medium and apparatus, and a recording medium having a test recording area for optimizing the recording and reproducing conditions (for example, see patent document 1).
Further, it is also proposed to enhance the optimization process efficiency (increase of speed of a starting process of the apparatus) by providing a drive information recording area for storing the result of optimization of recording and reproducing conditions by combining the recording medium and apparatus (for example, see patent document 2).
*** Patent Document 1: Japanese Patent No. 3099009
*** Patent Document 2: Japanese Patent No. 3285338
The above described methods, however, fail to refer to a process if a recording area for a specific application, such as test recording area or drive information recording area, becomes unusable.
If the test recording area is unusable, in the recording apparatus, the recording and reproducing conditions cannot be optimized, and it is difficult to assure the reliability of the recorded information. If the drive information recording area is unusable, in the recording apparatus, the result of optimization of recording and reproducing conditions cannot be stored, and thus an optimization process is required from the beginning when turning on the power source of the recording apparatus again or when replacing the recording medium. Accordingly an effect of speeding up of the starting process is lost.
An example of a case in which the specific application area becomes unusable, is known as a write-once medium. In the write-once medium, the same track cannot be recorded a plurality of times, and the number of times test recording or updating drive information is limited.
Or in a case of a recording medium being allowed to overwrite in the same track, if the number of times of rewriting is limited, such medium has the same problems. In particular, the test recording applies an excessive stress to the medium by overpower recording in a process of determining the optimum recording conditions, and the rate of deterioration is faster than in other areas, thus resulting in a problem in that the number of times of rewriting may be limited by the number of times of test recording.